Pond Boss Forums INTRO Questions & Observations Pond Shape vs. Fish yield

I've been reading the forum for several months to gain knowledge and acquaint myself with the issues you face as a pond owner. I bought 12 acres of land 7 years ago and built a house on it. Part of the appeal of this land was the apparent springs which formed a small creek in a ravine in the back of my property. The 'springs' issue will be for another topic. My question I would like to ask is 'How does pond shape affect the fish yield or carrying capacity of a pond. As I understand it, the bulk of the fish and the accompanying food chain reside in a band around the pond. Having a large amount of deeper, open water in the middle doesn't necessarily support a lot of fish especially in a LMB/BG pond. So a 1 acre pond that is 210' x 210' square would not have as much prime fish supporting water as a 1 acre pond that is 441' x 100'. Is that a correct assumption? Maybe it has no real world effect at all. Sometimes when you think about your dream to much you over analyze things. The reason I'm asking, is my potential pond site would be damming a 'ravine'. The shape would be long and narrow, maybe not even the 100' wide mentioned above. The shoreline on each side would be a bench approx 10-25' wide sloping to 5-6' deep with what is now the ravine bottom making a deep trench down the middle of the pond another 12' deeper and 15-25' wide. The main goal of my pond would be to support good eating, and I'm curious if the fish yields I've read in this forum would vary any according to the shape of the pond.

If you can understand what I'm trying to ask, I would appreciate any response you can give.

Tim

Yes shape will affect fish yield at least as I understand these things. But I'm not sure I have seen published reports that researched this concept.

You are correct the shallow zone along the shoreline results in more food production for the fish. This zone grows anoher form of algae/microinvertebrate community rarely discussed on this board. This community is called periphyton. Periphyton is composed of attached algae growth and the associated animals. This community can contribute a large percentage to the total pond or lake productivity. This zone where periphyton grows is called the littoral zone and is a very producive zone of lakes. Lake dynamics will determine weather the lake is plankton or periphyton dominated. This zone almost always corresponds to the depth of sunlight penetration to where rooted plants can grow. All this is especially true the clearer the water becomes in ponds (those not artifically fertilized).

Clearer water results in less planktonic growth and more periphyton growth.

The littoral zone of the pond or lake usually contains the highest concentration of fish due to it being a food producer. Weed beds and weed edges concentrate fish. Periphyton grows on structure in the littoral zone. The more shoreline you have, generally, the more fish or fish biomass will be produced (again in clear water situations). However at the same time you will also have to contend with more weed growth due to the increased amount of pond bottom area that can grow rooted vegetation and filamentous algae.

FYI - As far as I know most if not all the historical fish productivity studies and fertilization production studies were done in shallow water ponds. They also used smaller fish that fed lower on the food chain (planktonic organisms)and smallish predators. I'm not aware of scientific studies that used artificial fertilization and looked at producion /productivity of a fish commmunity that contained large predators (over 4-5 lbs)and compared this same water body to one with just "smallish" fish. Numerous fertilization studies have been done on moderate sized lakes in various parts of North America but I not familiar with how big the fish were in these lakes. The studies have probably been published.

Producivity as far as pounds of fish produced per acre may change as the size structure of the fish become larger. We are getting into theory here and many areas still need research.

Maybe some of the people that are familair with additional published reports can comment on this topic.

Thanks for the reply. Logically, it seems to me, that if any thing, a longer, narrower shape would be an advantage because of the higher percentage of prime productive waters. I just wanted to hear from you more knowledgable and experienced people what the disadvantages might be that I wouldn't have considered.

Thanks,

Tim

Main disadvantage is too much area for weeds to grow. Too many weeds or filamentous algae growth will limit your use of the pond (fishing - swimming, etc.). Too much of this "weed" growth usually results in use of chemical treatments and these treatments often suppresses the periphyton growth that contributes to the pond productivity and fishery and negates the optimum fish growing benefits of the littoral zone. One has to try and find a median somewhere in between all this.

Hopefully new technology will produce species specific weed control. I hope. I hope.

Tim – When I first read your post, I was impressed by the insight that you showed! Certainly, pond shape should be one of the primary factors that influences fish yield. Are you sure you are not some type of ecologist??
:-)

Wildlife biologists always look at the spacing and amount of various habitat types. In fact, one of my wildlife biologist friends always gives me a hard time. “Why the heck do you fish squeezers always talk about pounds of fish per acre of water? Why not pounds per cubic volume of water?”

I really had no “hard evidence” to give you for ponds, so I didn’t immediately respond. As usual, Bill responded, and with his typical thorough answer.

I have no doubt that you are right about pond shape. However, like Bill, I don’t know of any particular studies that focus on this topic for ponds. That doesn’t mean there are none, just that I haven’t seen them.

I think one reason for the lack of studies is simply that there are so many different factors that affect fish yield. One thing is certain: all ponds are NOT created equal, even when they are located close to each other. One pond may have higher water productivity (fertility) than another, and will support more pounds of fish than the other. One pond will be clear, while another will be muddy (that’s common even in fish hatcheries where side-by-side ponds are completely different). One pond will have few plants, another might have many. Types of plants present can vary between ponds. So, picking out just one factor in a study can be difficult.

Now, in reservoir studies, we actually do look at “shape” of the impoundment. We use an index called the “shoreline development index (SDI).” To get this number, you divide the shoreline length of the reservoir by the shoreline length of water body that is a perfect circle but of the same acreage. So, a reservoir that is perfectly round would have a SDI of 1.0. A reservoir that is long and narrow, with many arms and coves, will have a much higher value, often 10 or above. Whew! How’s that for wordy. Anyhow, we can clearly show increased fish abundance and sport fish yield in reservoirs with a higher SDI, if other factors (such as the fertility of the reservoirs) are similar.

Dave

Bill and Dave, thanks for the never-ending information you guys post for the rest of us
northern amateurs. Bill, I think you described my pond to a T. I couldn't understand
how(with very clear water and no feeding or fertilizing), I am getting good growth rates.
Thanks to you, I now have a clue. Two years ago, when I took over my pond (bass only, no
other fish) the first thing I did was to throw in some juvenile bluegill and perch 3" to 4 ".
This year I've already pulled out(and put back in) a 12" Y Perch and a 10" Bluegill both fat
and happy. I believe my pond has found that happy median you wrote of.It is appox. 4 1/2
acres, but it is shaped like a tomahawk or a hatchet with the "handle" being approx. 1acre of
shallows with allot of weed cover. The other 3 1/2 acres opens out and reaches a depth of
28'. You can stand on the shore and watch the bass swim into the "handle" to feed.

And, of course, a question for you guys. Are the any books , websites,newsletters, out there
with more info (generic not scientific) on periphyton growth. Also Bill, is there any way of
purchasing the article on Yellow Perch that you wrote a while back?

Thanks Jimmy

Jimmy - The rooted vegetation in the "handle" of your pond can, depending on plant species be a very beneficial area for producing tremendous numbers of insect larvae and other invertebrates (see later).

This food banquet is responsible for the rapid growth of the bgill and perch you mention. But,,, remember, this is not a limitless buffet. As your panfish numbers continue to expand to higher numbers the buffet size stays the same. This means that too many fish will be grazing on the same amount of food and each fish then gets less food and growth rates slow down. Fish growth rate in most cases is primarily dependant on food input. In a relatively newly stocked pond like yours, fish growth seems great the first few years; which is common. In the future, keep an "eye" on fish growth rates and densites,, and as growth slows and more smaller fish seem to be present or are showing up in the catch then numbers need to be thinned to maintain a balance between buffet size and number eating at the food bar. Growth of predators, body condition, and numbers also need to be monitored for the whole system to maintain a quality fishery. Too many fish present will be indicated by the average size is smaller for fish that are caught.

PERIPHYTON - Try google and search for periphyton. I'm not sure what will show up; probably lots of hits. I will try that method myself. You will have to sort thru it. I am not aware of generic information on periphyton. I'm not sure what more information you want to know. I could probably answer most of your questions. A limnology book wil give general aspects of it (understandable for a layman?). I deal with only technical aspects.

Many think of periphyton as only attached algae growth, but actually it is a whole community of microplants and tiny animals that live in this niche habitat. Some of the larger "critters" are comprised of grazing insect larvae up to 1.5" long (most 1/4"-1"). They feed, depending on food preferences, in and on the canopy of the periphyton growth.

Periphyton communities have labels (as to what type of substrate it is growing on. i.e. rock, mud, higher plant, wood etc. The communities are often composed of different species based on the substrate.

The leaves and stems of pond "weeds" in the handle of your pond no doubt contain lots of attached algae that serves as a food buffet. For example a single pondweed plant was carefully harvested from a lake in WI. All invertebrate animals (grazers) were washed off and identified. A total of 555 were counted. From this it was esitmated that a weed bed 60'x180' would have 30-33 million invertebrates at any one time during summer. Impressive. It's very hard to beat pondweeds for producing quality panfish in the littoral zone.

Come back if you run into things you do not understand.

Article about perch (3 parts) was writen for raising them in small ponds (one ac or less). Some of it would apply to larger ponds. The bigger the pond than 1 acre the less it probably applies. Back issues (fall03, winter04, spring04) are available from www.farmpondmagazine.com . I can as an alternative email you a copy of the manuscript or send you a photocopy. If you can wait, P.Boss magazine will also have an article by me about yellow perch this winter or spring.

Bill, good call, Google has 27,000 hits for periphyton. Also, I emailed FPM about back issues(they didn't have a link or a price). So I'll see if they get back to me.

As far as things I'm trying to find out, are there any major pitfalls to having this kind of ecosystem? As in, fertilization + feeding + thick ice + snow can = low DO and fishkill. Basically, is there anything I should be on the lookout for? Or, on the flip side, is there anything I can do to help this community. One thing I am thinking is that I have a ton of frogs, should I be thinning the frogs so there are more tiny insects for the smaller fish? This would be two-fold, if I toss frogs out into the middle of the pond, it would feed the bass. Besides the fact that my nephews get a kick out of watching the bass take out the frogs. The Bluegills have stuck and survived much better than expected, but the perch have been rare to catch or even see. So what I'm doing now is trying to grow out some perch in my fathead pond to reach a better survival size (thats the reason for wanting to obtain a copy of your raising perch article).

Thanks for taking the time Bill
much appreciated

Jimmy

bill c.

my office staff and i are amazed at how much you know about lakes.so with that we voted question of the day for you.as i've posted in the past i have a small lake about 5.2 acres that is about 3 1/2 years old that i fish along with employees.we do manage the lake(learning)and have enjoyed learning things from your post and others.so back to our question of the day.how many bass would there be on average in our lake,we have heard it carry;s about 50 pounds on average of bass per acre.is this correct? and if so is there a average we can change that pounds per acre to.example could there be 100 bass in the lake per acre for a total of 500 fish.the reason for the question is,myself and 3 guys were fishing saturday and caught 18 bass in about 3 hours of fishing,so we got to thinking just how many bass we must have passed up that did not hit our lures

Jimmy - I'll try and adress thes point by point.
1. Yes, I had the same response for my search of periphyton. A quick scan of the items indicatated it was almost all too technical and esoteric or specialized for the layman. I'm sure there are probably some simplified and generalized descriptions out there I just right now cannot think of any that are commonly available.

2. Frogs are having very little direct impact on the insect life (larvae) for small fish that I mentioned above in relation to periphyton community. Frogs, juvenile & adults, are feeding only on air borne insects). Tadpoles feed on algae and periphyton and probably some small invertebrates that too slow to escape the slow grazing tadpole. The insect larvae that I referred to as being associated with periphyton are immature stages of several thousand species of aquatic insects that occur in aquatic habitats of North America. Numerous patterns of these larvae are imitated by the fly fisherman's wet flies. These larvae spend a big portion of their life span underwater and then hatch or emerge, and as adults fly around, mate, lay eggs and die. This type of insect is commonly called and aquatic insect. Frogs only eat the adults not the larvae.

3. This periphtyon based type of ecosystem prevails in all ponds & lakes. The more underwater structure (surface area) that is present the more periphyton that will grow there since periphyton reqires a surface for attachment. As a general rule, repeat general, (not in all cases & exceptions do occur)the amount or height of the growth of periphyton tends to increase as the fertility increases providing adequate light hits the growing surface. When perphyton mats get too thick, they will slough off the surface and may float to the surface or sink. Surfaces are then quickly recolonized.

Water clarity determines how deep periphyton will grow underwater.

Also as the fertility increases and/or the nitrogen - phosphorus ratios change the compostion of species composing the periphyton community also change. This is one reason why periphyton communities are studied because the presence of certain species and/or species combinations can indicate environmental condition/health, changes in condition, nutrient enrichment or pollution levels.

4. Normally periphyton amounts are NOT abundant enough by themselves to cause oxygen shortages. More likely large die offs of aquatic rooted plants, filamentous algae blooms or phytoplankton blooms will be the major cause of your DO shortages. Associated peripyton deaths will also then contribute to the total oxygen losses due to bacterial decompostion of all the dead material. In your case the collapse of rooted weed bed growths in the pond's "handle" during winter will be more of a concern for DO loss in winter than the periphyton. This is why you may not want to let them get too thick or try and keep them confined to the shallow arm of the pond. Spot treatment of some of the weeds in the "handle" may be a viable option if you ever experience winter kills.

5. Note, chemical algae treatments also impact periphton growths since it is algae based or dominated.

6. Periphyton maintains healthy growths during winter if light intensities are adequate. Although species composition will likely be different during each season of the year.

7. Perch growout idea is a good idea in your case esp if you have LM bass present. Also practicing selective harvest and keeping the majority of bass in the smaller size range would help with improving the perch numbers.

More questions?

fish - Not enough time anymore tonight for your question. But will you highlight or select all of your question,,, go up to Edit (top left) and copy it as a new question located in the Forum of "Managing An Existing Pond" under the heading of "Evaluating and Adjusting Fish Populations". Someone in your "group" should be able to figure the method out. Your question belongs there not buried in the topic of "Pond Shape vs Fish Yeild" in general category of Questions and Observations. Thanks. Then I will attempt an answer tomorrow. Your question has lots of "it all depends" in the answer.

Bill, FPM got back to me, and for back issues it's buy 2 get one free, so at least I won't have to harrass you for the article. I don't really have any more question right now, more just a few comments.

As far as the frogs, I really didn't elaborate, and I apoligise for that.Along with the ton of frogs are millions of tadpoles, and at times all bunched up on the shoreline. I was thinking if I thinned out adult frogs and netted the tiny tadpoles,and trapped medium sized tadpoles I could take a lot of mouths off the buffet line. I did understand about the aquatic insects, the first thing that came to mind was Dragon fly larvae.

I'm not too concerned of a lack of DO, as I don't think my standpipe ever stopped running last year(and the outlet pipe is at least 12' to 15' below the surface). The weed beds have been contained to the "handle" and from now on I'll keep an eye on it to make sure.

I did "bother" you last year about growing out Bluegills in my fathead pond, but after seeing the Bluegills take root I switched it over to Perch. Having quite a few 12" to 16" bass in the big pond, how big would you recomend growing the Perch before tramnsplanting?

Seems I just can't post without asking a question.

Sorry for taking up all of your posting time!
Jimmy

A big portion of the tadpoles this time of year you have are probably toad tadpoles. Toad poles are in the pond only a short time (3 months)and in you area probably metamorphosed by 1st or 2nd wk of July. Periphyton should be able to easily handle tadpole grazing and will recover soon when tadpoles develped into frogs even the bull frog types. Tadpoles probably eat relatively few insect larvae.

Very good idea of switching to perch in fathead pond. I've seen 16" bass eat what looked like a 8.5" -9" perch; larger bass like'em that size. Plus your 16" bass will always be adding length. Catch one of those 16" bass and measure how wide its mouth is (inches). Then measure the body depth (height) of the perch you want to introduce. Newly stocked perch should be about the same size or larger than the mouth width of the bigger bass.

Thanks again Bill, you are the man!!
I don't believe there is anywhere else I could have learned so much about my pond in a couple of days.

Jimmy

This is litorally a most informative thread--thanks to all for the accumulation of knowledge it represents. Bill, when my pond was built the fellow who did the work put in what we call "Freddy's Finger," an offshoot of the main pond which is about 75' long, 20' across with relatively shallow grade and about 5' max depth. However, it doesn't have much bottom growth except, at its tip, some chara starting. The fish, LMB and BG (and some hybrids ) seem happy and are growing apace--probably counselling not messing with success--but I wonder if you would recommend introducing any bottom-growing plants to the Finger? Thanks!!

--Rick

I.I. Your pond must be relatively new. Nature will quickly take care of colonizing the finger with water plants. However with nature's common initial introductions (cattails, bullrush, Elodea, narrow-leaf pondweed, eurasian milfoil, chara) the finger will soon become "choked with weeds". The finger could become a "weed" management problem for you; time will tell. Sooner or later you will get most if not all of these, it just takes time. In my opinion keep all cattails OUT. They will start growth along shoreline or in water 2"-3" deep. Pull them. They can quickkly suround the finger and you will not be able to fish through or over them. They can grow 3'-4' deep which is almost all of your finger. Plant water-iris or spike rush in their place. You will like iris better than cattails for the finger in a smaller pond.

Chara you already have. It tends to be moderately good fish cover & forage areas, but it spreads very fast and thus removes nutriets from the water column fairly quickly to fuel the rapid growth (good&bad). As the beds get thick with several years of growth, the mud-water interface gets anoxic, and a thick layer of black septic smelly muck develops under the Chara mat. I think this is very counter productive to a healthy pond. I would try and remove (Lake Rake or Beechcomer rake)as much Chara as feasable as it develops.

If it was my pond in southern OH, I would try to get cork-screw or spiral eelgrass planted in the finger this summer (July-Aug). Some lily pond stores carry it. You are on the northern range for perenial growth of Corkscrew eel grass. It may not even survive winter in your planting-growth zone. C.screw (spiral) eelgrass does not get real tall 10"-14" and it oxygenates the sediments keeping them healthy. Fish can hunt through it pretty well since it does not form tangled masses. It has a slow to moderate rate of spread.

Hybrid water lilies would also be good in the finger but they may over time (6-10yrs) completely cover the finger. Thus only plant the ones you think are prettiest and ones that do not have the largest spreads of 8'-10' unless you want fast coverage. See items in the "search feature" on topics of water lilies for names for names of possible introductions.

Thanks, Bob. The pond is four years old, and I do have waterlilies and a variegated rush growing nicely in the finger. I have a couple of cattails, which I keep down to about 3'x3', none of which are along the finger. So far, the chara is barely noticeable, so I will work to keep it to a low to moderate level. I will scout around for the eelgrass, a recommendation I hadn't heard before. Thanks again!

--Rick